The present invention relates to a ring for sealing against fluid leakage (e.g. of gas or liquid) between two parts having mainly planar surfaces that are forced against each other. More particularly, the invention relates to the foregoing sealing ring for use where the two parts to be sealed comprise a cylinder block and cylinder head of an engine that operates at high pressure and high temperature, such as a combustion engine.
As a consequence of developing modern combustion engines, especially diesel engines, to achieve higher efficiency and power per liter of cylinder capacity, the pressure and temperature in the cylinders are increased. This results in major problems of sealing between cylinder block (e.g. a cylinder lining) and cylinder head.
Many different ways of solving the foregoing problem have been tried. For example, packings of hard or soft materials have been tried, as well as various shapes for the sealing surfaces. Also resilient sealing means of particular form have been tried.
The most common method of sealing multicylinder engines is to obtain, in the production process, the highest possible flatness of the mating sealing surfaces and to press, with high bolt forces, the two surfaces against the centerlines of the cylinders' perpendicular surfaces, with or without a packing in between. This means, however, that certain deformations of the surfaces may occur merely due to non-uniform static forces. During running, additional non-uniform forces result from pulsating gas forces caused by combustion pressure, and forces caused by temperature variations.
After a passage of sufficient time, other shape changes or exhaustion occur in the material, and as a consequence leakage of gas or liquid may occur.
Further drawbacks reside in the large number of hefty bolts and the large bolt forces required, which increase the dimensions of the affected parts, resulting in higher weight, and limiting the possibilities of achieving optimal technical solutions for flow and combustion.
The foregoing deficiencies are remedied or reduced by the present invention, which in one form, comprises a sealing ring for sealing against fluid leakage between mainly planar surfaces of a pair of parts that are mounted in forced relationship against each other. The ring, which is resilient, has a radially oriented annular section, and first and second ends projecting generally in opposite axial directions, respectively, from radially inner and radially outer portions of the annular section. The second end includes a first member projecting generally axially from the annular section, a second member projecting generally radially outwardly from the first member, and a third member projecting generally axially towards the annular member, such that the first, second and third members have a generally U-shaped cross-section. Radially outer surfaces of the first end and of the third member of the second end comprise sealing surfaces. Further, a pair of axially opposite surfaces of the annular section comprise generally parallel sealing surfaces.
A corresponding form of the invention also comprises a sealing ring for sealing against fluid leakage between mainly planar surfaces of a pair of parts that are mounted in forced relationship against each other. The ring, which is resilient, has a radially oriented annular section, and first and second ends projecting generally in opposite axial directions, respectively, from radially outer and radially inner portions of the annular section. The second end includes a first member projecting generally axially from the annular section, a second member projecting generally radially inwardly from the first member, and a third member projecting generally axially towards the annular member, such that the first, second and third members collectively have a generally U-shaped cross-section. Radially inner surfaces of the first end and of the third member of the second end comprise sealing surfaces. Further, a pair of axially opposite surfaces of the annular section comprises generally parallel sealing surfaces.
The recited radially outer or radially inner sealing surfaces are generally of cylindrical or conical shape. Such sealing surfaces are thus generally perpendicular to the mainly planar surfaces of the pair of parts that are mounted in forced relation against each other, such parts typically being the cylinder head and cylinder block of an engine. This means that the sealing surfaces of the ring and corresponding surfaces of the cylinder block and head, respectively, are minimally affected by the bolt and gas forces. Deformations, if any, are accounted for by the resilience of the ring, since the sealing forces are free to move with respect to each other.